Variable spacing mechanism for typewriting machines



April 13, 1948. T. JACKSON v2,439,470

VARIABLE SPACING MECHANISM TYPEWRITING'HACHINES Filed Nov. 14, 1944 5 Sheets-Sheet 1 "A -i113, 194s. ACR O 1' 2,439,470

VARIABLE SPACING MECHAIIISM FOB TYPEWRITING MACHINES Filed Nov. -14,' 1944 5 Sheets-Sheet 2 J EN O April 13, 1948. c. T. JACKSON VARIABLE SPACING MECHANISM FOR TYPEWRITING MACHINES Filed Nov. 14, 1944 5 Sheets-Sheet 3 TTOHNE Y I lllllllm April 13, 1948. 2,439,470

VARIABLE SPACING MECHANISM FOR .TYPEWRIT'ING MACHINES C. T. JACKSON 5 Sheets-She 4 LrEE Bill!!! IIIIII/II/II/I/lIII/III/IIIM/II III/III April 13, 1948. c, JACKSON 2,439,470

VARIABLE SPACING MECHANISM FOR TYPEWRITING MACHINES Filed Nov. 14, 1944 S-Sheets-Sheet 5 sM as A P54 Mums: CASE SPQCE I UPPER CASE SPACE H SH." 5w

fi UNIVERSAL am:

Mm @Mdml A TTORNEY Patented Apr. 13, 1948 VARIABLE SPACING MECHANISM FOR TYPEWRITING MACHINES Carlton '1. Jackson, Rochester, N. Y., asslgnor to International Business Machln es Corporation,

New York, N. Y a corporation of New York Application November 14,1944, Serial No. 563,349

1 This invention relates to typewriting machines. The primary object of the present invention is to provide an improved variable spacing mechanism suitable for use in a typewriter or other machine in which it is desired that the spacing of the printed characters be commensurate with the widths of the characters to enable so-called book type to be used.

An object is to provide a. variable spacing mechanism capable of producing a large'number of spaces, each different from the others.

An object is to provide a spacing mechanism capable of producing a variety of spacings which differ from each other in a very small degree.

An object is to provide a, variable spacing mechanism in which the spacings allotted to the different characters may be changed at will by the operator to any desired extent.

An object is to provide an electrically controlled spacing mechanism.

Another object is to provide a variable spacing mechanism which is capable of operating at high speed and therefore is more suitable for use in power operated typewriters.

An object is to provide an electrically controlled variable spacing mechanism with a manual switching mechanism which may be preset by the operator to determine the spacings of the characters to any desired extent and in which the spacings may be varied to a fine degree.

An object is to provide a variable spacing mechanism which eliminates the need for a power spring motor.

' An object is to provide a variable spacing mechanism suitable for operation by an electric torque motor.

An object is to provide a variable spacing mechanism in which the number of spacings allotted to the diflerent characters may be predetermined by means of an electric plugboard which may be changed at the will of the operator.

An object is to provide a variable spacing mechanism which is driven by an electrical torque motor in such a fashion as to make it possible to return the carriage without the use of a supplemental mechanism for that purpose.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, byway of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a vertical section of a power operated 19 Claims. (Cl. 197-44) typewriter suitable for use with the present invention and shows certain electric contacts employed in the present invention.

Fig. 2 is a rear view. partly in section, of the variable spacing mechanism and shows the connection thereof to the carriage of the typewriter.

Fig. 3 is a vertical section on the line 33 in Fig. 2.

Fig. 4 is a view of the variable spacing mechanism from the bottom.

Fig. 5 is a vertical longitudinal section of the variable spacing mechanism.

Fig. 6 is a perspective view showing the carriage return key and certain contacts controlled thereby. Fig. 7 is a wiring diagram.

In order to explain the purpose of the present invention it is shown in the drawings as applied to a well-known form of power operated typewriter known as the Electromatic." It will be understood, however, that the invention may be applied to other power operated typewriters or to manual typewriters with relatively minor changes not affecting the purpose or the basic features of construction of the invention. It will be understood that the typewriter consists of a well-known Electromatic" with the usual power driving spring motor and the usual carriage return clutch, tape drum, and tape connections omitted.

In Fig. 1 the usual. character keys are designated i0 and are pivoted on a fulcrum. wire Illa. These keys, through extensions lllb. control the cam units ll whichare mounted on the fulcrum wires l2 and cooperate with the usual power roller II which rotates continually in the direction of the arrow in Fig. 1 while the machine is in use. The cam units II are connected by the links M to the usual sub-levers II which are also pivoted on the fulcrum wire I001. The sub-levers.

II are connected by links it to the to gles I! of which there is one for each type bar l8. The type bars II are pivoted on the curved fulcrum wire I8 which is supported in the usual segment.

When the keys ID are depressed they operatively couple the cam units II to the power roller l3 and thereby the type bars l8 are operated to print upon a worlr sheet wrapped around the usual platen 20. The mechanism so far described is well-known in the art and it may be replaced by other well-known typing mechanism without affecting the operation 01' the invention described herein.

Associated with each key III is a pair of contacts designated K0 in Figs. 1 and 7 hereinafter work.

3 termed the key contacts. A similar pair of contacts designated BBC in Fig. 7 and called the space bar contacts are opcratedby a space bar or space key 2i (Fig. l) pivoted on the fulcrum wire a.

The sub-levers I! in the well-known "Electromatic typewriter operate a universal bar 22 (Fig. 1) which is pivoted at 22 in the main frame- Thls universal bar usually operates the ribbon feeding mechanism and in the present case it additionally operates a bar of contacts UBC through a finger 22a secured to the umversal bar 22 and arranged to close contacts UBC whenever a character is typed. The contacts KC and BBC are closed whenever a character key or space bar is depressed during the course of writing a line.

In place of the usual carriage feed rack of the "Electromatic and its cooperating feed pawls and power spring, there is provided the variable feed mechanism shown in detail in Figs. 2 to 5.

The platen (Fig- 2) is rotatably mounted in the usual carriage shown diagrammatically in Fig. 2 and designated 28 and includes a rack 28 meshing with a suitable idler gear 28 rotatable on a fixed part of the machine near its middle. This gear 28 meshes with a worm 21 by means of which a connection is established between the carriage 24 and the variable spacing mechanism to be described hereinafter. The worm 21, however, does not rotate in feeding the carriage but functions as a simple rack by longitudinal movement. It will be understood that any suitable means may be provided to prevent the worm 21 from rotating. For example, the left-hand end of the worm may be squared and guided by a square bearing, with the squared portion long enough to enable,the worm to travel far enough to feed the carriage 24 the width of the widest sheet which may be accommodated by the platen 28.

It will be understood that the pitch of the worm 21 and the size of. the gear 28 and rack 25 will be suited to the particular machine to which the invention is applied. The condition to be met is that the worm portion 21 shall be made at least long enough to permit the maximum travel of the carriage in typing a line plus the additional length necessary forthe worm to thread into the rotatable nut to be described hereinafter which forms part of the variable spacing mechanism. It is the rotation of this nut to cause the worm 21 to travel to the left that eflects the feeding move,- ment of the carriage during writing of the line.

The variable spacing mechanism is mounted on a frame which consists of two parallel circular plates 28 (Figs. 2 to 5) between which are mounted the spacing magnets or solenoids SM which.'

as shown in Fig. 3, are arranged in two concentric circular rows and staggered to obtain compactness. the magnets in each row being equal distances from the centers of the supporting disks 28. This frame and the magnets and other stucture mounted thereon may be mounted at any convenient place on or adjacent the typewriter but it will be assumed that it is mounted at the rear of the typewriter with the centers of the disks 28 in horizontal alignment with the axis of the worm 21 as shown in Figs. 2 and 3.

The plates 28 are Joined together by a long bushing 28 which is flanged at its left-hand and (Figs. 2, 4, and 5) and attached by screws to the left-hand plate 28. The other end of the bushing 28 is threaded into a collar 28 which is screwed tight against the right-hand face of the righthand plate a to clamp the solenoids BM between are looselyheld in the plates 22.

The bushing 22 serves as a bearing for a hollow shaft 2|, which is-keyed at its left-hand end (Fig. 5) to a pin drum 22 which, as will be made clear hereinafter. also acts as a brake drum. This pin drum 22 is formed with a plurality of radial slots 22a extending parallel with the axis of the shaft 2!. In these slots are slidably mounted the space controlling pins 22 which have limited sliding movement parallel to the shaft 2!. their normal position being tshl'iown in Fig. 5. The pins 22 e slots 2241 by a shroud ring 24 which may be pressed on the disk or drum 22. In order to frictionally hold the pins 22 when shifted in the slots there is provided retainers 28 consisting of a ball actuated by springs located in radial holes in the pin drum 22, each pin 28 having'its own ball retainer. Thus, the pins 22 will be held in the normal position of Fig. 5 or the projected position illustrated by the right-hand pin22inFig.4.

Each of the solenoids BM ha's'lts plunger 28 (Figs. 2 to 5) pivotally connected to a pin setting lever 21 pivoted on a post 28a carried by the lefthand plate 28. Normally the free ends of the levers 21 are alignedwith the ends of pins 22' whereby the energization of any solenoid SM will cause the corresponding pin 22 which happens to be in alignment with the lever of the energized solenoid to. be projected to the position shown at the left mm. 4. I

One of the solenoids is designated PRM in Figs. 3, 4, and? and will be known hereinafter as the pin release magnet. This solenoid has a long plunger 28a provided with a slot at its upper end through which passes a release lever 31a, one arm of which is provided with a bent-over lug 21b occup a'position Just over the pin 22 which happens to be active in preventing the rotation of the drum 22 as will be made clear hereinafter. The other arm of the lever 21a extends through a horizontal slot in a post 28 secured to the adjacent plate 28 to allow the lever 21a andthe solenoid plunger 28a to rock about the longitudinal axis of said plunger to a limited extent. The slot in the plunger 28a is longer than the width of the lever 21a where 1 it passes through the slot and there is provided a spring 28 surrounding the plunger 28a and interposed between the adjacent plate28 and a washer to so as to press the lever 21a upwardly against the'upper extremity of the slot in the solenoid plunger28a.

It will be understood that each of the plungers 28, 28a has a suitable stop internally of the solenoid to prevent withdrawal of the plunger from the coils more than a predetermined amount. Each of the solenoids SM is provided with a spring 28 which engages a similar washer 48 to press the plunger 28 upwardly to the limit permitted by the stop. The solenoids may be of any usual construction but it is preferred that they be as compact as possible in order that the size ofthe disks 28 may be kept within reasonable limits to avoid the spacing mechanism taking up too much space in the typewriter.

The pin drum 22 is formed with a tubular extension or hub 22!) (Fig. 5) on which is screwed a circular nut 8| locked in place on the extension 22b by means of one or more set screws la. The nut 4| is also threaded to receive the worm 21., It will be clear that rotation of the 21 to be advanced to the left in Figs. 2 and 5 according to the extent of rotation of the nut 4i. Thus, by variably rotating the drum 32 under control of the pins 33, the carriage may be caused to advance variable extents depending upon the extent of rotation of the pin drum 32.

Mounted on the right-hand plate 23 (Fig. 2) is an electric torque motor M, the frame of which is spaced from the plate 23 by means such as posts 42. The shaft 43 of this torque motor M (Fig. 5) is hollow to enable the worm 21 to travel to the right the extent necessary in returning the carriage after writing a line. The motor shaft 43 may be coupled to the shaft 3| by means which consists oi the disk 44 having pins .45 projecting into radial slots 43a in a disk 43 screwed on the right-hand end of the shaft 3| and locked thereto by one or more set screws 41. This permits-the motor to be removed ror servicing the mechanism.

The motor M is constantly energized while the machine is in use and normally tends to turn the pin drum 32 in a clockwise direction (Fig. 3). Rotation of the pin drum 33, however, is normally prevented by the fact that one of the pins 33 has beenproiected. as shown in Fig. 4 at the right, during a previous operation of the spacing mechanism to determine an increment of feed of the carriage. and engages a brake lever designated 43. This brake lever is rotatably mounted on the tubular extension 32b (Figs. 2 to 5) between the pin drum 32 and the nut 4|. This brake lever has the general shape shown in Fig. 3 and has a pin 43a to which is anchored a brake band 43 passing almost completely around theperiphery of the shroud 34 and anchored to a fixed pin 55 carried by the adjacent plate 28. Interposed between the brake band 43 and the shroud band 34 is a strip of brake lining 5|.

The .pin which was last projected into position to determine an increment of feed of the carriage engages the edge of the right-hand arm of lever 43 as shown in Figs, 3 and 4 and is in horizontal alignment with the lug 31b. The lug 31b extends into a transverse slot in the right-hand arm of lever 43 and is held in alignment with .the last projected pin by a spring 310 which urges the lever 31a in a counterclockwise direction (Fig. 3) to engage lug 31b with the bottom wall of the aforesaid slot. Since the motor M constantly tends to turn the pin drum 32 clockwise in Fig. 3, the projected pin will tend to rotate the lever 43 in the same direction thereby, through the pin 43a, applying tension to the brake band 43 causing the pin drum to be firmly gripped by the brake band and preventing rotation of the pin drum 32. In order to permit the projection of any or the pins 33 in the lower half of the pin drum in Fig. 3, and the rotation of the drum the lever 43 is cut away at 43b in two places to provide a space for not only the projection of the pin but its travel clockwise.

The mechanical operation of the parts so far described will now be made clear.

It will be assumed that both the magnet PRM and a selected one of the solenoids SM has been energized. This causes the projection of one 01 the pins 33 upwardly in Fig. 4 or to the lei't in Figs.--2 and 5 and at the same time the lever 31a is rocked counterclockwise (Fig. 4) torestore the previously set pin 33 now in alignment with the end of the lug 31b. The lug 31b pushes the previously set pin down far enough so that the upper end (Fig. 4 at the right) clears the edge of the lever 43. This releases the lever 43 and tension on brake band 43 and permits the pin drum 32 to rotate clockwise (Fig. 3) under the influence o! the torque motor M. The pin 33 which has been Projected upwardly in'Fig. 4 by the selected magnet SM now travels clockwise in Fig. 3 along with the pin drum 32 and eventually strikes the side of lever 43 and rocks it slightly in a clockwise direction. applying tension to the brake band 43. thereby stoppins the pin drum 32 in a new position.

The angular distance through which the pin drum 32 turns clockwise will depend upon the angular position of the setting lever 31 of the selected solenoid SM with respect to the lever 31a. In the illustrative embodiment shown in the drawings, with special reference to Fig, 3, there are provided 35 magnets BM besides the magnet PRM whereby there is a difference in rotation of the pin drum 32 of 10 between adjacent levers 31. Thus, any desired feed of the pin drum 32 between 10 and 350, with 10 difference may be obtained. Thus, it is'possible to obtain 35 different spacings which differ from each other by 10 of movement of the pin drum, since the magnet PRM is not used to determine the spacings of the carriage but s only to release the last set pin to permit spacing to be eil'ected. The magnets BM are designated SMI to SM35 in Fig. 7 and the numbering is considered to run in a counterclockwise direction (Fig. 3) so that the magnet BM35 selects the largest spacing and the magnet SMI the smallest spacing. Thus, if the numbers diflerentiating magnets SM in Fig. 7 are multiplied by 10, the number of degrees of rotation 01' the pin drum 32 in a counterclockwise direction will be denoted.

In Fig. 6 there is shown a mechanism for operating the carriage return contacts which are designated CRC in Figs. 6 and 7. Advantage is taken of certain mechanism usually provided in the Electromatic" for initiating and controlling carriage return operations for the same purpose in the present case. The carriage return key 53 controls a single lobe cam unit 54 which is pivoted on one of the fulcrum wires I2. when the key 53 is depressed the cam unit 54 is rendered operable by the cam roller l3 and is rocked in a counterclockwise direction. In the present case, the frame of the cam unit is provided with. extension arms 54a, in which is pivoted a roller 54b. This roller cooperates with one of the contact membars 55 carrying the contacts CRC in a manner to hold the contacts CRC open when the: cam unit 54 is in its normal position. When the cam unit is rendered operative by thekey 53 the rocking of the cam unit frame in a clockwise direction allows the contacts CRC to close which, as will be seen hereinafter, initiates a carriage return opably mounted on the main frame work. Pivoted at We on a bracket 55 secured'to the main frame work is a lever 5! which is connected with the lever 51 by a pair of toggle links 32. The lever 5| is urged in a counterclockwise direction by a spring 63 interposed between the lower arm of lever BI and a part of the worm housing 64. Normally the toggle composed of the links 52 and the lever 51 is opened downwardly with the common pivot below the dead center positions of the pivot 58 and the pivot of links 52 to lever 5|. When the cam unit 54 is operated, however. the lever 51 is rocked counterclockwise thus raising the common pivot a little above the dead center position and on extension 32a of lever 51 engages the end of the lever i. Since lever 5| is always under the tension of spring 53, the toggle comprising lever 51 and links 62 will lock in the upper all dead center position thereby holding the cam unit 54 in an operated position thus permitting the contacts CRC to remain closed. Cooperating with the lever 51 is a lever 65 pivoted at 55a on a fixed part of the machine. The lever 65 has one of its arms connected by a link 65 to the usual marginal stop trip mechanism which is ordinarily employed to disengage the carriage return clutch. This mechanism is not shown but it will be understood that the marginal stop strikes a lever which is connected by links, including the link 66, to the lever 65 so as to rock said lever clockwise when the carriage arrives in the left-hand marginal position. This trip mechanism is disclosed in Patent No. 2,098,319.

The rocking of the lever 65 in a clockwise direction causes the lever 51 to rock clockwise in Fig. 6 thereby breaking the locked toggle comprising lever 51 and links 62 and permitting the cam unit 54 to restore. For this purpose one arm of the lever 65 extends horizontally underneath the arm of lever 51 to which link 56 is connected. When the cam unit is rendered operative by depression of the carriage return key, the lever 51 is brought into contact with the horizontal arm of lever 65. Thus, when lever 65 is operated the lever 51 will be restored. The lever 51 only has to.

be moved slightly beyond the dead center position of the toggle to enable the spring 63 to be effective either to lock the toggle in upper oil dead center position or restore the cam unit 54.

With the exception of the contacts CRC, all of the mechanism shown in Fig. 6 is disclosed in the aforesaid patent. The structure shown in Fig. 6 diifers from the structure in the patent in that the usual carriage return clutch and tape drum has been removed and its place taken by the part 64 which may comprise a suitable plug or housing having an outboard bearing for the stub shaft which drives the power roller I4.

It is preferred that the machine be provided with a plugboard by means of which the operator may change at will the spacings allotted to the different characters, This,plugboard comprises a plurality of rows of plug sockets designated PSI which conveniently can be arranged in horizontal rows as in Fig. '7, each separate row being connected in common to one 01' the magnets SM35. Each horizontal row will be designated with a number denoting the number of space units which will result from energization of the corresponding magnet. Thus, in Fig. 7, the top row of plug sockets PSI corresponds to the magnet SM35 which produces the maximum spacing involvin 350 of rotation of the pin drum 32. The key contacts KC and the space bar contacts SPC are connected to the common terminals of a multi-contact shift relay SR. The normally closed and open contacts of the multi-contacts relay SR are connected to plug sockets PS2 and PS3, the normally closed contacts A being connected to PS2 and the normally open contacts B to PS3.

Under normal conditions with the shift relay SR deenergized, closure of any of the contacts KC will close a circuit to the corresponding plug socket PS2 through the associated normally closed contacts A of the shift relay. The plug sockets PS2 will be designated on the plugboard with the lower case letters or characters correspondlng to the key contacts KC with which they are associated. when the shift relay SR is energized, the circuits from all of the contacts KC will be transferred through contacts B to the plu sockets PS3 which will be identified on the plugboard with the upper case characters corresponding to the keys which control the contacts KC. The space bar contacts SBC are similarly connected to shift relay contacts A and B which lead to the plug sockets PS4, PS5 the purpose of which will be made clear hereinafter. I

Before using the machine the operator will insert plu connections between the plug sockets PSI to PS5 according to the spacing desired which will depend upon the nature of the type on the type bars, For example, a particular style of type might require 10 units of spacing for the upper case C and '7 units for the lower case c." Accordingly, the operator will insert the plug wires PWI, PW2 shown in dotted lines in Fig. 7 between the plug sockets PS2, PSI and PS3, PSI designated with the letters 0" and 0" and associated with contacts KC which are controlled by the C" key. Similar plug wires will be inserted for other letters but are not shown in Fig. '7 to avoid confusion. For the same reason, all of the key contacts KC and shift relay contacts are not shown.

If it is desired to space between words a greater extent for upper case characters than lower case characters, the plug sockets PS4 and PS5 also may be connected to the desired plug sockets PSI by plug wires PW3, PW4.

The operation of the machine as a whole will now be described. It will be understood that the carriage has been returned to the left-hand margin and that one of the pins 33 is in engagement with the edge of lever 48 preventing movement of the carriage by holding the brake band tight under the constantly applied torque of the motor M which tends to rotate the lever 48 in a clockwise direction (Fig. 3).

It will be assumed that the operator desires to indent the first paragraph and accordingly presses the space bar. This causes a circuit to be established from the line wire WI, through space bar contacts $30, the normally closed contacts A of relay SR to plug socket PS4, the plug wire PW3, plug socket PSI, and magnet SMB, to line wire W2, Magnet SM8 pushes into the path of the lever 48, the eighth pin in a counterclockwise direction (Fig. 3), not counting the one which now engages the lever 48.

The depression of the space bar 2| renders its cam unit operative to actuate a lever similar to the sub-lever I5 but not connected to a type bar and thereby actuates the universal bar 22 to close the contacts UBC. The contacts UBC close a circuit through the magnet PRM in parallel with the magnet SM8, thereby operating the lever 31a to disengage the pin 33 which engages the lever 48 from said lever in Figs. 3 and 4 permitting the motor M to turn the pin drum 32 in a clockwise direction (Fig. 3). Rotation of the pin drum in a clockwise direction causes the nut H to rotate to draw the worm 21 to the right (Fig. 2) sumciently to feed the carriage 8 units. When the drum 32 has rotated the pin which was set in operative position by the magnet SM8 will engage the lever 48 and rock itslightly clockwise to render the brake band eflective to stop further rotation of the drum 32. The operator, by depressing the space bar 2| 8. suflicient number of times, will cause the carriage to be advanced in steps each amounting to 8 units or spacing.

, contacts SKC similar to the contacts KC. This results in the energization of the shift relay SR by connecting it across the line wires WI, W2. The contacts B of the shift relay associated with key contacts KC close thereby connecting the "C" plug socket PS3 to the "0 key contacts. With the shift key held depressed manually or by means of the usual shift lock key to maintain the relay SR in energized position, the operator now depresses the "C" key thereby closing the C"- contacts KC. This causes a circuit to be established from line wire WI, the (3" contacts KC. contacts B of relay SR, the plug wire PW2, and magnet SMIII, to line wire W2. Th'e ener gizationof this magnet causes the tenth magnet SM in a counterclockwise direction (Fig. 3) to be energized thereby enabling the pin drum 32 to rotate 100 in a clockwise direction.

When the shift key is released the relay SR. is deenergized. It now the operator types a lower case character the circuit closed by contacts KC will go through one of the contacts A of relays SR and a plug wire PWI to a magnet .SM. As ordinarily the lower case letters are slightly narrower than the upper case characters, the plug Wires PWI 'will be plugged to magnets SM which cause lesser numbers of units of spacing. to be effected in printing the lower case than the corresponding upper case characters. This does not always hold true, however, as some of the keys have combinations of characters in which the lower case characters may be wider than the upper case characters. For example some of the numeral keys have characters which are printed by a case shift operation but are narrower than the numerals.

In printing titles it is sometimes desirable that the words of the title be separated by slightly greater spaces than in the context since titles are usually printed with capital letters. It may be found convenient to connect the plug socket PS5 by a plug wire to one of the plug sockets PSI to eifect a larger degree of spacing betweenwords when writing titles. This will effect considerable saving of time since usually it is necessary to press the space bar several times when spacing the parts of titles.

The torque motor M may be used to return the carriage under control of the contacts CRC controlled by the carriage return key 53. When the carriage return key is depressed, causing the contacts CEO to close, the motor relay MB is energized. Normally the coils Cl, C2 (Fig. 'l) of the torque motor M are connected as shown in Fig. 7

for forward rotation. When the relay is energized one of the coils Cl is reversed causing the motor M to rotate in the opposite direction. At the same time, it is necessary to reset the pin 33 which engages the lever 43. This effect is produced by the closure of contacts A of the motor relay MR which establishes a circuit through the pin restoring magnet PRM thereby releasing the pin.

Contacts B of relay MR also close and energize the momentary impulse relay MIR. The armature 10 of this relay is beveled at its end to cooperate with a bevel on a tooth II a of a slide 1i pivotally slidably mounted at 12. A spring 13 urges the slide ll both to the left and in a clockwise direction against a stop pin 14 which engages a cam surface lib formed in the slide 1|.

10 The slide II has a finger 'llc cooperating with a pairs of contacts PSC called the pin setting The initial energization of magnet MIR. merely causes the armature 10 to wipe past tooth lie and rock the slide ll counterclockwise a slight extent, the tooth Ila snapping behind the armature I3. The spring I3 is weaker than the spring II for the armature Ill. The relay MIR is maintained energized during the returnof the carriage by the effect of the toggle comprising lever 31 and links 62 (Fig. 6) as explained above. As soon as the motor MB. is reversed it starts to return the carriage by rotating nut ll counterclockwise (Fig. 3). When the marginal stop reaches the left-hand marginal position, the link 66 will be drawn to the right (Fig. 6) by the marginal stop thereby bending the toggle past dead center and permitting the restoration of the cam unit 54. Thereupon the cam unit reopens the contacts CRO deenergizing the relay MIR, permitting the spring ll to restore the armature 10. Through the cooperation of the tooth Ha with the end of the armature 13, the slide 'Il is pushed to the right thereby closing contacts PSC. This causes the magnet SMI to be energized setting the first pin 33 inc. counterclockwise direction from the lever 31a (Fig. 3). In its movement to the right (Fig. '7) to close contacts PSC, the slide II is cammed in a counterclockwise direction by the effect of pin 14 on cam surface lib so as to free tooth Ila from armature 10 just after contacts PSC close allowing slide II to restore'to the position of Fig. 7 and allowing contacts PS0 to reopen. Thus, contacts PSO close only momentarily when coil MIR is deenergized. Thus when the motor M is reconnected by the relay MB. to turn in a forward direction, the pin set 33 by magnet SMI will allow the pin drum 32 to rotate 10 clockwise and engage the lever 48 thus aligning the carriage in the left-hand marginal position. It will be understood that the marginal stop and the main stop which arrests the carriage in the marginal position will be so related that when the carriage is returned, it is returned slightly more than one unit space farther than the left-hand marginal position. This is done to insure that the pin 33 which is set by the magnet SMI will have sufllcient clearance to be sure to engage the lever 43. An ideal way would be to push up the pin 33 which stops'underneath the lug 31b but this would not be possible, first because there is no provision for projecting the pin in this position; and, second, if there were such provision, the pin would strike the underside of the lever 48 since the brake band is released at this time and lever 43 has been shifted slightly counterclockwise thus obstructing the movement of this pin.

The circuit through contacts PSC and the provision for feeding the carriage a little beyond the final marginal position is equivalent to the provision in standard typewriters having escapements for overrunning the margin sufllciently to enable the escapement dogs to engage the teeth in the escapement wheel or rack.

There are cases where it may be desired to release the spacing mechanism and accordingly there is provided thepin release contacts PRC in parallel with the universal bar contacts UBC. Manual closure of the contacts PRC by means of a suitable key causes the pin release magnet PRM to be energized to release the pin 33 which is,

7; holding the pin drum. This will permit the car- 11 riage to be driven in a letter space direction by motor M. g

A pin setting key is provided which actuates contacts PSK (Fig. 7),, -When this key is operated it closes a circuit to any selected one of the magnets SMI to SMJI which may have been plugged to plug socket PS8. This sets the pin 33 corresponding to the selected magnet allowing the carriage to stop after the contacts PRC have been used to cause the carriage to run free in a letter spacing direction. The keys controlling contacts PRC and PSK may be used to obtain longer movements of the carriage than may be obtained by the space bar.

As a means of indicating to the operator the condition of the mechanism there is provided a signal light L which is extinguished while the carriage is being returned. This light should always be on when the spacing mechanism is in normal condition with the motor M energized.

While there have been shown and described and pointed out the fundamental novel features of the invention by means of a single illustrative embodiment. it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In combination with the carriage of a typewriter, a feed screw connected to the carriage, a feed nut for said screw, a pin drum for driving said nut and having a series of selectively pro- Jectable pins, a brake for said pin drum including a brake lever engaged by a projected pin to set said brake and hold said pin drum immobile, means to release said projected pin from said lever to free said pin drum for rotation, means to selectively project another of said pins simultaneously with the release of the pin engaging the brake lever, and motor means for turnin said pin drum until the selectively projected pin engages said lever.

2. In combination with the carriage of a typewriter, a pin drum having connections to said carriage for feeding the latter in a letter spacing direction and including a series of pins selectively projectable, a brake for said pin drum including an operating lever engaged by a projected pin to hold said pin drum and said carriage immovable. means for selectively projecting one of said pins,

means for releasing the projected pin from said brake lever to permit the pin drum to rotate to a new position determined by the selectively projected pin, and motor means for rotating said pin drum to said new position. I

3. In combination with the carriage of a typewriting machine, a drum havinga driving connection to the carriage for feeding said carriage in a letter spacing direction, stop elements and operable to set the associated element to writing machine, a rotary member having a driving connection to the carriage for feeding it in a letter spacing direction, a series of stop members mounted on said rotary member for movement from an ineffective position to a stop position, a series of selector magnets corresponding to said stop members; setting levers actuated by said magnets and mounted independently of said rotary member and arranged to register with said stop members when the rotary member is in a predetermined stopping position determined by setting of one of said stop members in stopping position, said magnets when energized actuating said levers to set the associated stop members in stopping position: stopping means for said rotary member normally cooperating with one of said stop members to hold said rotary member immovable in the predetermined stopping position to thereby prevent movement of the carriage in a letter spacing direction, a magnet for restoring the stop member which cooperates with the stopping means to thereby permit rotation of the rotary member to a new position determined by the setting of another of said stop members by one of said magnets, and means for rotating the rotary member when said set stop member is restored.

5.'In a typewriter, the combination with the carriage of a pin drum having a connection to the carriage to drive the latter in a letter spacing direction and including a series of pins movable from an ineifective position to a drum stopping position, means to selectively set said pins in drum stopping position including a series of setting members mounted independently of said drum and registering with said pins, each setting member when operated setting the pin in registry therewith to drum stopping position, stop means cooperating with the said pin to arrest said drum after an extent of rotation thereof determined by the angular position of the set pin on said drum; means registering with said set pin, when in the drum stopping position in cooperation with said step means, for restoring the set pin to permit rotation of said drum; means to selectively operate said setting members along with the restoring of the set pin, and means to rotate said drum upon the restoration or said pin.

6. In combination with the carriage of a typewriting machine, variable spacing mechanism for said carriage including a rotary member having a plurality of stop elements each settable to a position limiting rotation of said member; stop means cooperating with a set stop element to arrest said rotary member after an extent of rotation determined by the angular position of the set stop element, one of said stop elements normally preventing rotation of said rotary member; means to restore the set stop element to release said rotary member for rotation, means operative with the restoration of the set stop element to selectively set another stop element, and means for rotating the rotary member upon the restoration of the set stop element.

7. In combination with the carriage of a typewriting machine, a support frame, a stop drum rotatably mounted on said frame, stop elements mounted on said drum in a row concentric with the axis of rotation and settable to a position limiting rotation of the drum, a series of setting levers mounted on said frame with one arm of each in register with one of said stop elements stopping position, a series of selector magnets assauo '13 mounted on said frame, each for operating one of said levers, a brake for said drum including a brake lever pivoting coaxially with said drum and engaged by a set stop element for partial rotation thereby to set the brake and arrest said drum, a release lever mounted v21 said frame and registering with the set stop element 'in the brake setting position, a release magnet for operating said lever to release the set stop element, motor means normally tending to rotate said drum. means connecting said drum to said carriage whereby rotary movements of said drum feed the carriage in a letter spacing direction, character keys, and contact means rendered effective by said character keys for selectively operating one of the selector magnets and also causing an operation of the release magnet.

8. In a typewriter, the combination with the carriage of a rotary member having a driving connection to the carriage; a series of stop elements mounted on the rotary member, each for determining a 'diiferent extent of rotation of said member and settable from an inactive position to a stop position; a series of character keys, means controlled by said keys for selectively setting said stop elements, means cooperating with the set stop element to arrest the rotary member and normally preventing rotation of the rotary member by cooperation with the stop element set by a previous operation, and means operative when a stop element is set to release the previously set stop element to permit rotation of the rotary member an extent determined by the position of the selectively set stop element on the rotary member.

9. In a. variable spacing typewriter, variable spacing mechanism including a rotary stop member having a series of stops disposed at different angular distances about the axis of rotation of said member and settable to determine different degrees of rotation of the stop member, means to selectively set said stops including a series of setting levers registering with said stops when the rotary stops member is at rest and a series of eleotromagnets for operating said levers, each for operating one of said stops; mechanism forprintcurrently with the printing of a character, electromagnetic switching means connected to said magnets and contact means for enabling each character key to control a plurality of said magnets according to the condition of said electromagnetic switching means, and contact means controlled by said shift key for controlling the electromagnetic switching means to change the selection of said magnets by said first contact means when the case shift mechanism is rendered operative to print characters in a difierent case ing type faces of different widths, character keys selectively controllin the character printed, contact means closed by operation of said keys, and manual switching means to at will connect said contact means to said magnets to predetermine the extent of spaces accorded each character printed.

10. A variable spacing typewriter having printing mechanism arranged to print a font of characters having different widths, character keys for controlling the printing mechanism to print the characters of said font, contact means controlled by said keys, variable spacing mechanism including a series of magnets each for causing a different extent of feed of the carriage, and manual switching means for connecting said contact means to any of said magnets to enable the operator to at will change the extent of feed imparted to the carriage for any character printed.

11. In a variable spacing typewriter, the combination of means for printing a font of characters having difierent widths, character keys for controlling the printing mechanism to print the characters of said font, variable spacing mechanism including a plurality of space selecting elements eachfor causing a different width of character spacing, and means manually selectively settable by the operator for selectively coupling said keys to any of the selecting elements of said whereby case shifted characters will be spaced diil'erently from non-case shifted characters.

.13. In a variable spacing typewriter, printing mechanism adapted to print characters in different cases and difl'erent widths, character keys for controlling the printing mechanism, contact means controlled by said character keys; variable spacing mechanism including a series of electromagnets for selecting spacings, each magnet determining a different degree of spacing; a shift relay having contacts connected to said contact means, a shift key, contact means controlled by said shift key for controlling said relay, and manual switching means for connecting the contact means of said relay to said magnets to predetermine the magnets selected and arranged to cause the first contact means to selectdiflerent magnets upon a case shift operation from those selected normally.

14. In combination with the carriage of a typewriter; variable spacing means including a rotary stop member connected to the carriage and having a series of stops each projectable to an effective position and representing different extents of spacings, one of said stops being normally projected; stop means engaging the normally projected stop to prevent rotation of the rotary stop member, means for projecting said stops to effective position to determine an increment of spacing, means for restoring the previously projected stop concurrently with the projecting of a new stop, a torque motor connected to said rotary member for rotating the latter to space the carriage when said previously projected stop is restored, a carriage return key, means controlled by the carriage return key for reversing said motor and releasing the previously projected stop to permit the rotary stop member to be driven in a reverse direction by said motor to return said carriage, and margin control means for disabling the motor reversing means when the carriage reaches the marginal position.

15. In combination with the carriage of a variable spacing typewriter, variable spacing means including a rotary stop member connected to the carriage andhaving a series of stops each projectable to an effective position and representing different extents of spacings, one of said stops being normally projected; stop means engaging the normally projected stop to prevent rotationof the rotary stop member, means for projecting said stops to effective position to determine an increment of spacing, means for restoring the to be driven in a reverse direction by said motor to return said carriage, margin control means for disabling the motor reversing means when the carriage reaches the marginal position, and means controlled by said motor reversing means for pro- .iecting one of said stops when the carriage reaches the marginal position.

16. In a typewriter, the combination with the carriage of a rotary member having a feeding connection to the carriage, selectively settable stop means on said rotary member, brake means cooperating with the selectively settable' stop means to hold the rotary member immobile, means for selectively setting said stop means to determine the extent of rotation oi. the rotary member, means for at the same time releasing the brake means: and means to rotate the rotary member,

when the brake means is released, to move the carriage to a new position determined by the selective setting of the stop means.

17. In a typewriter, the combination with the carriage of a rotary member having a feeding connection to the carriage, selectively settable means on said rotary member representing different spacings of the carriage, brake means actuated by the selectively set means to hold the rotary member immobile, means for selectively setting said settable means to determine the extent of rotation of the rotary member, means for at the same time rendering the brake means momentarily ineffective; and means to rotate the rotary member, when the brake means is rendered ineflective, to move the carriage to a new position determined by the selective setting of the settable means. 1 v

18. In combination with the carriage of a typewritmg machine, variable spacing mechanism for said carriage including a rotary member having a feeding connection to the carriage andhaving means selectively settable to positions limiting rotation 01 said member; means cooperating with the settable means to arrest said rotary member after an extent of rotation determined by the settin 4 of the settable means, said cooperating meigjenormally preventing rotation of said rotary me r; means to restore the settable means to release said rotary member for rotation, means operative with the restoration of the settable means to selectively set the settable means, and means for rotating the rotary member upon the restoration of the settable means.

19. In combination with the carriage of a typewriting machine; variable spacing mechanism tor said carriage including a rotary member having driving connection to the carriage and including release said rotary member for rotation, means to selectively set another element, and means for rotating the rotary member upon the release of the previously set element.

CARLTON T. JACKSON.

REFERENCES CITED The following references are of record in the file of this patent:

.. UNITED STATES PATENTS Number Name Date 559,325 Ellis Apr. 28, 1896 559,326 Ellis Apr. 28, 1896 580,654 Templeton Apr. 18, 1897 1 698,966 Kitsee Apr. 29, 1902 781,441 Mayer Jan. 31, 1905 1,286,186 Miller Nov. 26, 1918 2,211,911 Reid Aug. 20, 1940 2,366,914 Le Clair et ai. Jan. 7, 1945 

